The invention relates to a profiling roller for producing a profiled grinding wheel for a thread grinding machine working with longitudinal feed, having at least one finishing roller rib in the center of the roller, with a flank angle, root radius, depth of thread and pitch circle radius corresponding to the thread to be produced, and modified preliminary roller ribs with decreasing rib height arranged symmetrically in relation to both ends of the roller.
In known rollers for the rolling of thread profiles in grinding wheels of thread grinding machines operating with longitudinal feed, the profile is so arranged that each of the ribs have a uniform angle, which corresponds to the flank angle of the workpiece to be ground. Furthermore the ribs are so graduated in height that the height of successive ribs increases from one end of the roller to the other so that the ribs located at the terminus have a height which corresponds to the finished thread profile. In this structure the adjacently located smaller ribs take over the function of the preliminary roller, so that the excavated material is shared between the individual ribs. As a rule three different heights of rib are arranged for preliminary rollers, increasing in height from one end of a roller to the other, and for finishing grinding two or three ribs with uniform height are provided.
These known profiling rollers have the marked disadvantage that they can only be used for grinding in one direction. Furthermore in these known rollers, which have a uniform flank angle on all ribs, there is no possibility of selecting a radius for the teeth greater than that prescribed for the finished profile. The tooth radius is the weakest point of a profile in performing rough grinding.
In U.S. Pat. No. 2,787,798 an arrangement is disclosed in which the flank angles vary towards the rib root but are equal above the pitch circle diameter. Such a device cannot be used for rolling profiles in a grinding wheel.